How can one intellectually respond to the specious argument that the Holy Qur’an was quoted from previous books (the Torah and the Gospel), and what is the evidence against quoting the cosmic verses specifically?

The specious claim that the Quran was اقتباس (borrowed or plagiarized) from the People of the Book is baseless, as there is no single piece of evidence to prove it. The Quran itself refuted the claims of the disbelievers of Mecca that Prophet Muhammad, peace and blessings be upon him, learned from a human, affirming that he was illiterate, neither reading nor writing, and that the Quran itself consists of clear verses. Moreover, the Prophet, peace and blessings be upon him, never received knowledge from the People of the Book. This specious claim is closer to a baseless whisper (waswasah), and one should overcome it by seeking knowledge and reading specialized books that refute these assertions.